Aging from adolescence to adulthood is a challenging developmental period for all youth, but it is especially difficult for youth with autism spectrum disorders (ASDs). Just when these youth need help the most, they face three major service transitions: loss of entitlement for services as they age out of eligibility for special education;potential loss of health insurance coverage as they age out of eligibility for their parents'private insurance or public insurance programs;and the shift to adult services systems. The prevalence of ASDs is approximately 70 per 10,000, affecting an estimated 560,000 children and youth ages 0-21. Autism spectrum disorders impair multiple domains of health, mental health, and development throughout the life course. These pervasive impairments result in complex service needs that cut across sectors, change as people age, and demand a high degree of service coordination. Timely access to appropriate and well coordinated services has the potential to improve health, mental health, functional outcomes, and quality of life in adulthood, thereby reducing the public health burden of disease. Very little is known about how service use and insurance coverage change as youth with ASDs age into adulthood, or how these changes are related to health and functional outcomes in young adulthood. We propose, in this R01 application from a new investigator, to test hypotheses using data from a nationally representative and diverse cohort of 922 youth with ASDs followed over nine years into young adulthood. These panel data are being prospectively collected via the U.S. Department of Education's National Longitudinal Transition Study 2. We have developed an innovative conceptual model of service transition that synthesizes and tailors previous models to fit this unique population. We propose three specific aims: 1) To characterize the changing service needs, service use and health insurance coverage as adolescents with ASDs age into young adulthood. We will assess mental health, health, educational, and social service domains;2) To discover resources and barriers associated with use of, and continuity in patterns of service utilization;and 3) To characterize young adult outcomes (functional, behavioral, and health) and examine how these are associated with antecedent measures of need, service use, resources, and barriers. Our study directly addresses the NIMH Systems Research Program's area of emphasis on "research on the delivery, access, and effectiveness of services for adults with autism." We will also help meet one of the key short-term objectives of the Interagency Autism Coordinating Committee's strategic plan to support at least two studies to assess and characterize service access, health, and functional outcomes stratified by demographic characteristics by 2011. Our study would be one of the most socioeconomically and racially diverse studies of adolescents and adults with ASDs ever conducted in the U.S. PUBLIC HEALTH RELEVANCE: Very little is known about how service use and insurance coverage change as youth with autism spectrum disorders age into adulthood or how these patterns of change are related to health and functional outcomes in young adulthood. The primary public health significance of our study is that it will begin building a foundation of population-representative evidence that can inform the development and evaluation of services for the growing population of youth with autism spectrum disorders. Our study will directly address two priorities of NIH: the NIMH Systems Research Program's declared area of emphasis on "research on the delivery, access, and effectiveness of services for adults with autism" and the Interagency Autism Coordinating Committee's goal to support studies to assess and characterize service access, health, and functional outcomes stratified by demographic characteristics.